This invention relates generally to self propelled devices for cleaning submerged surfaces such as found in swimming pools. More particularly, it relates to friction feet which support swimming pool cleaners relative to and engagable with a surface to be cleaned.
Mechanical pool cleaners which utilize the flow of water drawn through the cleaner by means of a connecting flexible suction hose in communication with a filtration system pump are well known. Such pool cleaners are termed suction cleaners. Some suction cleaners include devices to establish reciprocating, impulsive, and vibratory forces useful for providing the propulsive force to move the cleaner in a random manner across the surface to be cleaned.
In U.S. Pat. No. 3,803,658 to Raubenheimer, an apparatus is disclosed which uses a repetitive variation in the flow of fluid through the apparatus to submit various components to variable loads and thereby impart stepwise movement to the apparatus across the surface to be cleaned.
A suction cleaner described in U.S. Pat. No. 4,023,227 to Chauvier uses the oscillatory movement of a flapper valve located in the operating head of the cleaner to impart impulsive forces to the apparatus for the purpose of moving the apparatus along the surface to be cleaned. U.S. Pat. Nos. 4,133,068, and 4,208,752 to Hofmann also use an oscillatable valve located in the head of the cleaner to provide impulsive forces to the apparatus for the purpose of moving the apparatus along the surface to be cleaned.
U.S. Pat. Nos. 4,682,833 and 4,742,593 to Stoltz and Kallenbach, respectively, disclose the use of an expansible tubular diaphragm to achieve a pulsating flow of fluid through the cleaner assembly and resultant forces suitable for the displacement of a pool cleaning apparatus over a surface to be cleaned.
Other means to provide impulsive, vibratory forces to a pool cleaner device are disclosed in U.S. Pat. No. 4,807,318 to Kallenbach, U.S. Pat. Nos. 4,769,867 and 4,817,225 to Stoltz and U.S. Pat. No. 5,404,607 to Sebor.
U.S. Pat. No. 4,434,519 to Raubenheimer describes a suction cleaner having at least one friction support attached directly to the frame of the cleaner for engaging the submerged surface. The cleaner uses turbine means to impart reciprocating vibratory forces to the frame oblique to the submerged surface and alternately acting through the friction support in two opposed directions, the force in a first direction tending to lift the friction support from the surface and the force in the second direction tending to push the friction support back onto the surface, the resulting effect of said oblique forces and the bias caused by suction causing the apparatus to advance over the surface in a step by step manner. The friction support is a pivotally mounted foot projecting at an angle to the submerged surface and biased towards the vertical of said surface. Further improvements and a later embodiment of the aforementioned device were disclosed by Raubenheimer in U.S. Pat. No. 4,536,908.
U.S. Pat. No. 5,293,659 to Rief et al. discloses the use of a vibrator device and inclined bristle supports which work together to cause forward movement of the cleaner over the surface to be cleaned. Rief ""659 discloses bristle supports inclined resilient supports. The term xe2x80x9cresilientxe2x80x9d is described as being the inherent characteristic of the support itself to bend. The bottom ends of the supports are offset from their corresponding top ends in a common direction.
In view of the foregoing background, it is therefore an object of the present invention to provide improved friction supports for incorporation into swimming pool devices which, in order to achieve forward motion, use the action of reciprocating vibratory forces and such friction supports in engagement with a submerged surface to be cleaned. In particular, it is an object of this invention to improve upon the stiff pivotally mounted friction supports known in the art by integrally forming the resilient biasing means with a stiff, support. This will reduce the number of components and simplify assembly and maintenance. A further object is to integrally form the pivot means or fulcrum with either the housing or the support itself. This will further reduce the number of components, simplify assembly and maintenance. It is yet another object to provide means which will enable oscillatory movement of a stiff or generally rigid support without the need for engagement of the support against a shaft or fulcrum. Yet another object is to use resilient membranes which are predisposed to deform in a desired manner to provide oscillatory movement of the free end of a support, regardless of whether or not the support is initially oriented at an angle to the surface to be cleaned. It is also contemplated that the system and method are useful in fluid environments other than swimming pools and spas. Further, the invention will be useful for incorporation with xe2x80x9cpressure endxe2x80x9d swimming pool cleaners which operate on the return flow of fluid from a pump, through a flexible hose connected to the cleaner and into the swimming pool.
According to the present invention, there is provided a device for cleaning surfaces submerged in a liquid. A swimming pool cleaner operable through a vibratory movement thereof is provided and comprises a housing, vibrating means carried by the housing for providing a vibratory movement thereto, a friction support carried by the housing at a first orientation thereto for operably engaging a surface to be cleaned, the friction support having a first end pivotally attached to the housing, and a second free end in frictional contact with the surface to be cleaned, and biasing means operable between the housing and the friction support for biasing the friction support toward the first orientation and limiting movement thereof, which movement displaces the free end and thus the support from the first orientation to a second orientation.
The cleaner is in communication with a suction pump and motor by means of a flexible elongated hose connected to a coupling located on top of a housing. The cleaner housing incorporates at least one suction chamber comprising an entrance end in proximity to the submerged surface to be cleaned and an exit end communicating with the coupling. A vibrator device is located within at least one suction chamber. At least one support is attached relative to the device for engaging the submerged surface to be cleaned. The support may be partly or wholly manufactured from a rubber-like friction material. Its free end may integrally incorporate or be capable of receiving an attachment incorporating a protuberance, shape, dimension or surface characteristic which will provide a frictional grip against the surface to be cleaned.
During operation, an inertial mass forming part of the cleaning device, energized by a vibratory device into vibratory or to-and-fro motion, acts through the friction supports to generate reciprocating forces oblique to the surface to be cleaned and in at least two opposed directions in turn, the force in an upwards direction tending to lift the support from the surface and the force in a downwards direction tending to push the friction support back onto the surface, the resultant of the downward force and the downward bias caused by suction, causing the apparatus to advance over the surface in a step by step manner.
All of the supports disclosed have the following common characteristic: Their free ends are all capable of oscillatory movement between two positions; typically a few millimeters.
First embodiments of substantially rigid, stiff friction supports (i.e. supports which do not bend and straighten along their length) are pivotally mounted to the cleaner device at an angle to the surface to be cleaned, such that, upon application of a downward force, the support will oscillate about an axis generally lateral to the downward force, the improvement being that means to return the friction support to the first position upon removal of the downward force are integrally formed with the friction support.
Second embodiments of friction supports are attached and oriented such that the point of contact by each support""s free end against the surface to be cleaned is directly below the point of attachment of the support relative to the housing (i.e. the supports are not inclined), the shape of the support between the latter points designed such that, upon application of a downward force, at least a portion of the support will flex and thus produce a resultant force including a component capable of moving the cleaner device in a forward direction.
Yet other embodiments of friction supports have at least two points of attachment with respect to the housing such that lines drawn between the points of attachment of each support and the point of contact by each support""s free end against the surface to be cleaned will not incline in a common direction.